ICS411 PC PERIPHERAL CLOCK. Description. Features. Block Diagram DATASHEET

Transcription

1 DATASHEET ICS411 Description The ICS411 is a cost-effective clock synthesizer developed to optimize component count for PC motherboard and peripheral applications. The device supports a common, low cost MHz crystal. The device locks all output frequencies to enhance system performance. By supporting common PC peripheral interface frequencies including 25 MHz for Ethernet and MHz for audio and other applications, the device lowers chip count enhancing system cost and reliability. Features Low operating voltage of 3.3 V Accepts MHz clock input to lower jitter Fixed dual 25 MHz clocks for Ethernet Fixed MHz clock Power consumption of 15 ma (typ) extends battery life Duty cycle of 45 to 55% (24.576M) Packaged in 8-pin SOIC (Pb-free) Contact IDT for custom frequency requirements The ICS411 utilizes a low pin count 8-pin SOIC package to optimize board space. IDT is a leader in low jitter and power consumer application clock sources. These devices are capable of supporting CCD, video, audio, USB, CPU, and other peripherals. Block Diagram VDD ICLK MHz PLL M 2 GND IDT / ICS 1 ICS411 REV E

2 Pin Assignment ICLK 1 8 VDD VDD 2 7 GND GND M Pin (150 mil) SOIC Pin Descriptions Pin Number Pin Name Pin Type Pin Description 1 ICLK Input Clock connection. Connect to MHz clock. 2 VDD Power Connect to voltage supply. 3 GND Power Connect to ground M Output MHz clock output. 5 Output 25 MHz clock output. 6 Output 25 MHz clock output. 7 GND Power Connect to ground. 8 VDD Power Connect to voltage supply. IDT / ICS 2 ICS411 REV E

3 External Components Series Termination Resistor Clock output traces over one inch should use series termination. To series terminate a 50Ω trace (a commonly used trace impedance), place a 33Ω resistor in series with the clock line, as close to the clock output pin as possible. The nominal impedance of the clock output is 20Ω. Decoupling Capacitor As with any high performance mixed-signal IC, the ICS411 must be isolated from system power supply noise to perform optimally. Decoupling capacitors of 0.01µF must be connected between each VDD pin and the PCB ground plane. PCB Layout Recommendations For optimum device performance and lowest output phase noise, the following guidelines should be observed. 1) 0.01µF decoupling capacitors should be mounted on the component side of the board as close to the VDD pin as possible. No vias should be used between decoupling capacitor and VDD pin. The PCB trace to VDD pin should be kept as short as possible, as should the PCB trace to the ground via. 2) To minimize EMI the 33Ω series termination resistor, if needed, should be placed close to the clock output. 3) An optimum layout is one with all components on the same side of the board, minimizing vias through other signal layers. Other signal traces should be routed away from the ICS411. This includes signal traces just underneath the device, or on layers adjacent to the ground plane layer used by the device. Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the ICS411. These ratings, which are standard values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical parameters are guaranteed only over the recommended operating temperature range. Item Supply Voltage, VDD All Inputs and Outputs Ambient Operating Temperature Storage Temperature Junction Temperature Soldering Temperature Rating 7 V -0.5 V to VDD+0.5 V 0 to +70 C -65 to +150 C 125 C 260 C Recommended Operation Conditions Parameter Min. Typ. Max. Units Ambient Operating Temperature C Power Supply Voltage (measured in respect to GND) V IDT / ICS 3 ICS411 REV E

4 DC Electrical Characteristics VDD=3.3 V ±10% Notes: 1. Nominal switching threshold is VDD/2 Parameter Symbol Conditions Min. Typ. Max. Units Operating Voltage VDD V Input High Voltage V IH Note V Input Low Voltage V IL Note V Output High Voltage V OH I OH = -25 ma 2.4 V Output Low Voltage V OL I OL = 25 ma 0.8 V Operating Supply Current IDD No load 8 ma Short Circuit Current I OS Each output 80 ma AC Electrical Characteristics VDD = 3.3 V ±10%, Ambient Temperature 0 to +70 C Parameter Symbol Conditions Min. Typ. Max. Units Input Frequency MHz Output Rise Time t OR 0.8 to 2.0 V, C L =15 pf 0.60 ns Output Fall Time t OF 2.0 to 0.8 V, C L =15 pf 0.60 ns Output Clock Duty Cycle At VDD/2, M % Absolute Jitter, Short Term Variation from mean, 150 ps M Absolute Jitter, Short Term Variation from mean, 115 ps IDT / ICS 4 ICS411 REV E

5 Package Outline and Package Dimensions (8-pin SOIC, 150 Mil. Narrow Body) Package dimensions are kept current with JEDEC Publication No. 95 Millimeters Inches* 8 Symbol Min Max Min Max A A B INDEX AREA E H C D E e 1.27 BASIC BASIC 1 2 D H h L α *For reference only. Controlling dimensions in mm. A h x 45 A1 - C - C e B SEATING PLANE.10 (.004) C L Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature 411MLF ICS411LF Tubes 8-pin SOIC 0 to +70 C 411MLFT ICS411LF Tape and Reel 8-pin SOIC 0 to +70 C Parts that are ordered with a "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant. While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology(IDT) assumes no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments. IDT / ICS 5 ICS411 REV E

6 Innovate with IDT and accelerate your future networks. Contact: For Sales Fax: For Tech Support Corporate Headquarters Integrated Device Technology, Inc Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. Printed in USA